1. Field of the Invention
The present invention relates in general to a tamper-evident container closure and a container neck structure. More particularly, the present invention relates to a closure which is applied with an axial downward force onto the neck. After the tamper-evident feature of the invention is removed, the cap may be screwed onto and off the container as a reclosure cap.
2. Description of the Related Art
The snap-on, screw-off structures available in the prior art are of two general types--those having thread engagement as initially applied, and those without initial thread engagement. The no-thread initial engagement system has the major advantages of being simple to manufacture and apply, and achieving good reseal on reclosure through the thread torque. However, using a liner closure with this system is somewhat difficult and the consumer may be confused by the requirement of twisting the closure relative to the neck after the container is initially opened by a lifting motion. An example of a closure having no-thread initial engagement is taught by U.S. Pat. No. 4,561,553 to Crisci.
A system having full thread engagement during the initial application has several advantages over the no-thread system, including the ability to easily use lined closures and the elimination of consumer confusion. However, the initial thread engagement systems do not offer the manufacturing and application advantages available with the no-thread system. With the thread system, the closure must be twisted relative to the container at some point during the application process. An example of such a closure is shown in U.S. Pat. No. 4,625,875 to Carr.
The present invention provides full thread initial engagement by reason of a unique thread design, a unique tamper-evident band and means of orienting the closure and container threads to achieve registration prior to straight axial application. The present invention offers considerable advantages over prior structures as is evident from the description of the related art and the following description of the invention.